Tottenham booked a place in the EFL Cup final as Moussa Sissoko and Son Heung-min got the goals in a 2-0 victory over Brentford.
Thomas Frank's Championship promotion-chasers headed into the match bolstered by a 16-match unbeaten run and victories over four other Premier League sides in this season's competition, but Sissoko's 12th-minute header punctured any early enthusiasm.
The visitors posed enough questions of Spurs in their usual eloquent style and Ivan Toney had a 63rd-minute header disallowed for offside.
Son then streaked clear of their defence to hammer home his 16th goal of the season and grant Tottenham boss Jose Mourinho his latest shot at silverware.
Brentford finshed with 10 men after Josh Dasilva's ugly lunge caught Pierre-Emile Hojbjerg.
They had given themselves an uphill task by allowing Sissoko far too much room to glance home Sergio Reguilon's left-wing cross in a first half of few chances.
Toney outmuscled Davinson Sanchez to get on the end of Bryan Mbeumo's floated 34th-minute delivery, although Hugo Lloris was equal to a looping header.
The Brentford striker arguably caused his own goalkeeper more discomfort when Lucas Moura's header from Son's corner spun off Toney, with David Raya saving superbly as he tumbled backwards to his left.
Serge Aurier made a vital last-ditch challenge to thwart Toney after Mbeumo got the better of Sanchez five minutes into the second half.
Aurier and Son spurned presentable chances and Toney thought he had equalised for Brentford, only for a VAR review to show he was fractionally offside.
That close shave roused Spurs from their second-half torpor and Harry Kane combined with Tanguy Ndombele for the latter to slide Son through for an emphatic finish.
A spirited Brentford were sapped by that strike and needed another impressive intervention from Raya to prevent Kane from adding further gloss to the scoreline.
Dasilva was deservedly dismissed six minutes from time after leaving Hojbjerg with an ugly gash on his shin.
What does it mean? Mourinho's League Cup love affair continues
Mourinho has lifted the three-handled trophy on four occasions and it was his first honour in English football with Chelsea back in 2005. It was also the last major prize Spurs were able to collect, back in 2008. Victory over either of the other semi-final combatants - his former club Manchester United or Pep Guardiola and holders Manchester City - would surely by richly enjoyed by Mourinho if he and his players can complete the job at Wembley in April.
Son breaks through Tottenham's second-half gloom
Things were threatening to get a little dicey for Spurs until Son stepped up. Of course, that is what attackers of the highest calibre tend to do on the big occasion. No Tottenham player had more shots (three) or shots on target (two) than the South Korea superstar, who also made a team-high three key passes. Only Kane, with 17, can better his all-competitions haul this season. Liverpool's Mohamed Salah also has 16 goals.
Bees indiscipline stings
Brentford have wowed with their champagne football in the second tier over the past two seasons, but perhaps a rash side to their game reared its head in north London. Already on a yellow card, Sergi Canos had an unusually lenient Mike Dean to thank when he hacked down Lucas. Dean had no choice when Dasilva left Hojbjerg bloodied and understandably furious.
Both sides turn their attention towards the FA Cup this weekend, with Brentford hosting Championship counterparts Middlesbrough and Spurs travelling to non-league Marine in the most intriguing tie of the third round.